Magnitude and Predictive Factors of Difficult Airway in Patients Undergoing Thyroid Surgery, From a Goiter Endemic Area

The role of an enlarged goiter for the airway management in patient populations undergoing thyroidectomy has rarely been studied. The main objective of this study was to assess the incidence and predictive factors of difficult airway in patients undergoing thyroidectomy. The study was designed as a prospective observation carried out to determine the incidence of difficult mask ventilation, difficult laryngoscopy, difficult intubation and failed intubation. Association of goiter related variables and demographic characteristics association with difficult airway was analyzed using chi-square, fisher's exact taste and binary logistic regression with odds ratio and 95% CI in the univariate analysis. Sensitivity, specificity positive predictive value and negative predictive value for bedside airway parameters were calculated. For the preoperative bedside airway parameters Roc analysis with a CI of 95% and p-value 40 years), deviation of the trachea (>1 cm on chest x-ray), jaw slide (B or C), mouth opening (<3 cm) were identified as a potential risk factors in the univariate analysis. With multivariate analysis tracheal deviation was identified as the only independent risk factor for DL or DI. Patients with DL (CL III/IV) required repeated attempts of laryngoscopy (≥ 3) for intubation. The use of smaller size endotracheal tubes was helpful in managing patients in who calculated size ETT were difficult to pass through a narrowed or deviated trachea. We conclude that thyroid enlargement accompanied by airway deformity constitutes a risk factor for both difficult laryngoscopy and intubation. Preparation of different size endotracheal tubes as well as ordering a preoperative chest x-ray is recommended.